The knee is the largest and most complex joint in the human body and the largest weight-bearing joint in the body. The more weight it bears, the greater the chance of wear and tear of the joint cartilage and the faster it degenerates.
After middle age, the tendons and ligaments of the knee joint begin to undergo degenerative changes, the synovial fluid secretion in the joint cavity decreases, the bone surface of the joint forms bone wear, and the tissue around the joint is prone to fibrous adhesions due to inflammation, so the elderly often feel stiffness in the knee joint and make a “click” sound or friction sound when moving. This can lead to pain, swelling, joint effusion and, in severe cases, joint deformity and disability.
How can we take care of our knees to avoid joint wear and tear? First, we need to understand the developmental degeneration process of the knee joint and the load on the knee joint during various postural activities.
The human knee joint has 15 years of optimal condition
Before the age of 15.
The knee joint is in the developmental stage, and most of the growing pains of adolescence occur near the knee joint.
From 15 to 30 years of age.
The knee joint is in “perfect condition” and works tirelessly. As long as the knee joint tissue is not damaged, it is basically not felt.
Ages 30-40.
The patellofemoral cartilage develops early and mild wear and tear, and a period of weakness occurs, with short-term knee pain that lasts a few weeks to a few months and is not even noticeable in some people. Patellofemoral cartilage is a 3 to 5 mm thick layer of clear cartilage in the human knee joint that cushions the knee joint from the impact of movement.
However, because the patellar cartilage has no nerve distribution, it will only sound an “early warning signal” once during the vulnerable period before the full layer wears out, and strenuous exercise should be avoided during this period. From this time on, the knee joint can no longer be used as you wish.
From 40 to 50 years old.
After walking long distances, the inside of the knee joint tends to become sore and painful, which is relieved by rubbing it with your hands. In the knee joint, the meniscus serves to cushion vibrations and maintain stability. Since 60% of the body weight is supported by the medial side of the knee joint, degeneration of the medial meniscus occurs earlier. Because of the nerve distribution in the meniscus, people can feel soreness and pain during the degeneration process. This phenomenon is a reminder that it is time to start taking care of your joints.
Over 50 years of age.
This is because the patellofemoral cartilage has reached the end of its “useful life”, the cartilage is worn down and arthritis has developed. This is the time to conserve the use of the joint, reduce strenuous exercise, especially stairs and climbing, and use crutches if necessary to reduce the stress on the knee joint.
The knee weight-bearing multiplier is as follows.
1.When lying down, the weight-bearing of the knee is almost 0.
2.When standing up and walking, the weight on the knee is about 1 to 2 times.
3.When going up and down slopes or up and down steps, the weight on the knee is about 3 to 4 times.
4.When running, the weight on the knee is about 4 times.
5.When playing ball, the weight of the knee is about 6 times.
6, squatting and kneeling, the knee weight is about 8 times.
Daily care for sore knees.
1, do not walk for too long, when the knee feels uncomfortable should be immediately rest.
2, do not do a large amount of exercise, such as running, high jump, long jump.
3, avoid half squat, full squat or kneeling position, such as squatting horse stance.
4.Do not do half flexion rotation of the knee joint to prevent half plate injury.
5, maintain the ideal weight to reduce the burden on the knee.
6, pay attention to the warmth of the knee, you can wear long pants, knee pads to protect the knee.
7, less heavy lifting, less wearing high heels.
8.Avoid trauma and overwork.
9, the choice of shoes is very important. A pair of shoes that fit can not only make you walk comfortably, but also reduce the impact and pressure on the knee during exercise.
(1) the instep part of the foot can be closely combined with the shoe, width, length are appropriate, can correctly maintain the arches of the foot.
(2) the weight of the shoe to light, the sole should not be too soft, and to a little thickness.
(3) The heel of the shoe can be about 2-3 cm high, the sole is too flat is easy to walk when fatigue.
(4) shoes with non-slip pattern on the sole.
Through the appropriate muscle strength, stability training can play a preventive health role for the knee joint
1, side lying exercises: lying on the left side, knees slightly bent, heels together. Head resting on the left arm, eyes looking straight ahead. The right hand holds a weight of about 1 to 2 kg, placed on the outside of the leg. Then tense the abdomen, tense the hips, lift the knee of the right leg as high as possible, hold the body still while lifting the leg, hold for a few seconds and put it down. Repeat the exercise 15 times, change legs.
2, leg lifting exercises: stand behind a solid bench or step, step on the right foot (heel do not hang), and focus the weight on the right foot, the body is raised, the left foot toes touch the step, hold on for 1 to 5 seconds. Then lower the left foot and tap the ground. Repeat 8 to 10 times, change legs.
3, bridge exercise: lie flat on the ground, knees bent, feet apart, hip-width apart, arms on the sides. Slowly lift the hips and leave the ground smoothly. Then slowly put down. Repeat 15 times.
4, leg extension exercise: lie flat, knees bent, feet flat on the ground. Extend the left leg, set into the stretching band or towel, hands grasp the ends of the band. Use the strap to pull the leg to the chest, and then force the calf straight, hold for 10 to 30 seconds to exercise the calf muscles and hamstrings. Repeat the movement 3 to 5 times, then switch legs.